feat(api): add ResolveSpec and WebSocket client implementations

- Introduced ResolveSpecClient for REST API interactions.
- Added WebSocketClient for real-time communication.
- Created types and utility functions for both clients.
- Removed deprecated types and example files.
- Configured TypeScript and Vite for building the library.

resolvespec-js/PLAN.md

@@ -0,0 +1,132 @@
+# ResolveSpec JS - Implementation Plan
+
+TypeScript client library for ResolveSpec, RestHeaderSpec, WebSocket and MQTT APIs.
+
+---
+
+## Status
+
+| Phase | Description | Status |
+|-------|-------------|--------|
+| 0 | Restructure into folders | Done |
+| 1 | Fix types (align with Go) | Done |
+| 2 | Fix REST client | Done |
+| 3 | Build config | Done |
+| 4 | Tests | Done |
+| 5 | HeaderSpec client | Done |
+| 6 | MQTT client | Planned |
+| 6.5 | Unified class pattern + singleton factories | Done |
+| 7 | Response cache (TTL) | Planned |
+| 8 | TanStack Query integration | Planned |
+| 9 | React Hooks | Planned |
+
+**Build:** `dist/index.js` (ES) + `dist/index.cjs` (CJS) + `.d.ts` declarations
+**Tests:** 65 passing (common: 10, resolvespec: 13, websocketspec: 15, headerspec: 27)
+
+---
+
+## Folder Structure
+
+```
+src/
+├── common/
+│   ├── types.ts             # Core types aligned with Go pkg/common/types.go
+│   └── index.ts
+├── resolvespec/
+│   ├── client.ts            # ResolveSpecClient class + createResolveSpecClient singleton
+│   └── index.ts
+├── headerspec/
+│   ├── client.ts            # HeaderSpecClient class + createHeaderSpecClient singleton + buildHeaders utility
+│   └── index.ts
+├── websocketspec/
+│   ├── types.ts             # WS-specific types (WSMessage, WSOptions, etc.)
+│   ├── client.ts            # WebSocketClient class + createWebSocketClient singleton
+│   └── index.ts
+├── mqttspec/                # Future
+│   ├── types.ts
+│   ├── client.ts
+│   └── index.ts
+├── __tests__/
+│   ├── common.test.ts
+│   ├── resolvespec.test.ts
+│   ├── headerspec.test.ts
+│   └── websocketspec.test.ts
+└── index.ts                 # Root barrel export
+```
+
+---
+
+## Type Alignment with Go
+
+Types in `src/common/types.ts` match `pkg/common/types.go`:
+
+- **Operator**: `eq`, `neq`, `gt`, `gte`, `lt`, `lte`, `like`, `ilike`, `in`, `contains`, `startswith`, `endswith`, `between`, `between_inclusive`, `is_null`, `is_not_null`
+- **FilterOption**: `column`, `operator`, `value`, `logic_operator` (AND/OR)
+- **Options**: `columns`, `omit_columns`, `filters`, `sort`, `limit`, `offset`, `preload`, `customOperators`, `computedColumns`, `parameters`, `cursor_forward`, `cursor_backward`, `fetch_row_number`
+- **PreloadOption**: `relation`, `table_name`, `columns`, `omit_columns`, `sort`, `filters`, `where`, `limit`, `offset`, `updatable`, `recursive`, `computed_ql`, `primary_key`, `related_key`, `foreign_key`, `recursive_child_key`, `sql_joins`, `join_aliases`
+- **Parameter**: `name`, `value`, `sequence?`
+- **Metadata**: `total`, `count`, `filtered`, `limit`, `offset`, `row_number?`
+- **APIError**: `code`, `message`, `details?`, `detail?`
+
+---
+
+## HeaderSpec Header Mapping
+
+Maps Options to HTTP headers per Go `restheadspec/headers.go`:
+
+| Header | Options field | Format |
+|--------|--------------|--------|
+| `X-Select-Fields` | `columns` | comma-separated |
+| `X-Not-Select-Fields` | `omit_columns` | comma-separated |
+| `X-FieldFilter-{col}` | `filters` (eq, AND) | value |
+| `X-SearchOp-{op}-{col}` | `filters` (AND) | value |
+| `X-SearchOr-{op}-{col}` | `filters` (OR) | value |
+| `X-Sort` | `sort` | `+col` (asc), `-col` (desc) |
+| `X-Limit` | `limit` | number |
+| `X-Offset` | `offset` | number |
+| `X-Cursor-Forward` | `cursor_forward` | string |
+| `X-Cursor-Backward` | `cursor_backward` | string |
+| `X-Preload` | `preload` | `Rel:col1,col2` pipe-separated |
+| `X-Fetch-RowNumber` | `fetch_row_number` | string |
+| `X-CQL-SEL-{col}` | `computedColumns` | expression |
+| `X-Custom-SQL-W` | `customOperators` | SQL AND-joined |
+
+Complex values use `ZIP_` + base64 encoding.
+HTTP methods: GET=read, POST=create, PUT=update, DELETE=delete.
+
+---
+
+## Build & Test
+
+```bash
+pnpm install
+pnpm run build    # vite library mode → dist/
+pnpm run test     # vitest
+pnpm run lint     # eslint
+```
+
+**Config files:** `tsconfig.json` (ES2020, strict, bundler), `vite.config.ts` (lib mode, dts via vite-plugin-dts)
+**Externals:** `uuid`, `semver`
+
+---
+
+## Remaining Work
+
+- **Phase 6 — MQTT Client**: Topic-based CRUD over MQTT (optional/future)
+- **Phase 7 — Cache**: In-memory response cache with TTL, key = URL + options hash, auto-invalidation on CUD, `skipCache` flag
+- **Phase 8 — TanStack Query Integration**: Query/mutation hooks wrapping each client, query key factories, automatic cache invalidation
+- **Phase 9 — React Hooks**: `useResolveSpec`, `useHeaderSpec`, `useWebSocket` hooks with provider context, loading/error states
+- ESLint config may need updating for new folder structure
+
+---
+
+## Reference Files
+
+| Purpose | Path |
+|---------|------|
+| Go types (source of truth) | `pkg/common/types.go` |
+| Go REST handler | `pkg/resolvespec/handler.go` |
+| Go HeaderSpec handler | `pkg/restheadspec/handler.go` |
+| Go HeaderSpec header parsing | `pkg/restheadspec/headers.go` |
+| Go test models | `pkg/testmodels/business.go` |
+| Go tests | `tests/crud_test.go` |